quot;Benefits of OSPF Incremental SPF OSPF uses Dijkstra#39;s SPF algorithm to compute the shortest path tree (SPT). During the computation of the SPT, the shortest path to each node is discovered. The topology tree is used to populate the routing table with routes to IP networks. When changes to a Type-1 or Type-2 link-state advertisement (LSA) occur in an area, the entire SPT is recomputed. In many cases, the entire SPT need not be

recomputed because most of the tree remains unchanged. Incremental SPF allows the system to recompute only theaffected part of the tree. Recomputing only a portion of the tree rather than the entire tree results in faster OSPF convergence and saves CPU resources. Note that if the change to a Type-1 or Type-2 LSA occurs in the calculating router itself, then the full SPT is performed.

Incremental SPF is scheduled in the same way as the full SPF. Routers enabled with incremental SPF and routers not enabled with incremental SPF can function in the same internetwork.quot;

Question No: 149

Refer to the exhibit.

The Cisco Nexus 1000V in the VMware vSphere solution effectively creates an additional access layer in the virtualized data center network; which of the following 1000V characteristics can thedesigner take advantage of?

Offloads the STP requirement from the external Access layer switches

If upstream access switches do not support vPC or VSS the dual-homed ESX host traffic can still be distributed using virtual port channel host mode using subgroups automatically discovered through CDP

Allows transit traffic to be forwarded through the ESX host between VMNICs

Can be divided into multiple virtual device contexts for service integration, enhanced security, administrative boundaries, and flexibility of deployment

Answer: B Explanation:

quot;Virtual Port Channel Host Mode Virtual Port Channel Host Mode (vPC-HM), shown in Figure 5-33 , allows a port channel from the Cisco Nexus 1000V to be terminated on two separate upstream switches, even if these switches do not support a clustering technology, such as vPC or VSS.quot;

Question No: 150

The network designer needs to consider the number of multicast applications and sources in the network to provide the most robust network possible. Which of the following is a consideration the designer must also address?

The IGPs should utilize authentication to avoid being the most vulnerable component

With SSM source or receiver attacks are not possible

With Shared Trees access control is always applied at the RP

Limit the rate of Register messages to the RP to prevent specific hosts from being attacked on a PIM-SM network